1

Dual Drive-By-Wire Throttle

Body Harness Installation

PN 558-411

Instruction Manual – 199R10593

PN 558-411 is designed for use with dual throttle bodies.

To ensure a safe and reliable installation, there are certain hardware requirements that must be followed:

Only the following factory DBW throttle bodies have been pre-calibrated and approved for use with this harness:

 GM P/N – 12570790

 GM P/N – 12580760

 GM P/N – 12605109

 GM P/N – 12570800

2.0 Warnings!

Use only the drive-by-wire wiring harness supplied by Holley. THIS HARNESS CAN NOT BE CUT, SHORTENED, LENGTHENED,

TAILORED, OR MODIFIED UNDER ANY CIRCUMSTANCE! THE HARNESS CONTAINS PROTECTIVE SHIELDING / GROUNDED

CABLING TO ENSURE PROPER OPERATION. DO NOT REMOVE OR MODIFY THE PROTECTIVE SHEATHING UNDER ANY

CIRCUMSTANCES. HOLLEY ASSUMES NO LIABILITY FOR ANY INSTANCES ARISING DUE TO USE OF THROTTLE PEDALS,

THROTTLE BODIES OR ASSOCIATED COMPONENTS NOT SPECIFICALLY APPROVED BY HOLLEY.

2

3.0 Installation

Installation of both the drive-by-wire throttle bodies and pedal assembly should be performed by a professional, competent mechanic. It

is important that the installation of both the throttle bodies and pedal assembly on an engine (not originally equipped with these

 The accelerator pedal must have adequate clearance throughout the range of its travel to prevent the possibility of the pedal

coming in contact with any item that may cause it not to return to the “idle” position upon release. The accelerator pedal must

also be mounted far enough away from the brake pedal as to allow for the vehicle’s brakes to be fully applied without the

operator’s foot coming in contact with the D-B-W pedal.

 The drive-by-wire pedal should be in a position such that it is lower than the brake pedal when the brake pedal is depressed.

 Installation of the wiring harness supplied by Holley must be done so that there is no chance the wiring may be cut or abraded.

Rubber grommets should be utilized wherever the harness passes thru a firewall / sheet metal panel.

 The DBW harness should never be routed in such a manner that it may come in contact with “noisy” electrical components or

wiring that may emit RFI and/or EMI noise. Typical “noisy” components and associated wiring in a vehicle would be spark plug

wires, ignition coils, high energy ignition boxes, two-way radios (including CB’s), etc. Maintain a minimum of 5” of clearance to

4.0 System Safeties

Holley designed the drive-by-wire system to utilize a brake pedal switch input. This is wired to a +12v input from the brake pedal

switch. If the brake pedal is depressed enough to activate the brake light switch, the following occurs:

 The ECU will not allow a pedal position over 10%, no matter how far the pedal is pushed. This consequently limits the

opening of the throttle bodies.

Before a pedal value over 10% will be recognized, the following must occur in this order:

Most drive-by-wire systems are designed so there are two position sensors on both the throttle body and the accelerator pedal

assembly. This is done as a failsafe in the event that one of the position sensors should fail. Holley EFI systems require that both sets

of sensors are functioning 100% properly. If any sensor moves from its calibrated position, the throttle body is immediately de-

powered, forcing it to move to the factory “limp home” position. The “limp home” position is described in detail below. Whenever a fault

is detected and the throttle body is de-powered, a fuel flow limit of 30 lb/hr is also introduced.

5.0 Throttle Body “Limp Home” Position

It should be strongly noted that this position allows MORE airflow than the engine uses for an idle position. If the throttle body goes into

a “limp home” position due to a sensor failure or other reason, the engine will have more air and result in more power. This will require

more brake pressure to be applied if a vehicle is in gear so that it does not move.

3

6.0 Software Setup

Drive-by-wire software MUST be installed correctly before attempting to start the engine. The Drive-By-Wire Individual Configuration

File (ICF) must be installed. The installer/tuner/operator should review the Software Operation sections in the tuning manual to

Once the drive-by-wire ICF is added, first select the “Throttle Body Type” in the Throttle Body Setup. ONLY use throttle bodies that are

in this dropdown. They are listed by the OEM part numbers. These throttle bodies have been calibrated by Holley to function properly.

If the idle “surges”, it may be necessary to slow the idle control strategy. It may be necessary to utilize the “custom” setting for the

Advanced Idle Control (top dashed circle). See Figure 1 below. It is recommended to type in all the settings in the “Idle Control

Parameters” as shown, as a start (bottom dashed circle). Use these as a start and tune as necessary.

6.1 Tuning the Pedal vs. Throttle Table

first cell in this table is limited to a value of 20%, the second cell 30%, and the fourth cell 40%. All other cells allow for the throttle body

to be commanded to 100% throttle body opening.

4

7.0 Checks To Perform After Installation and Before Starting

Before starting an engine with Holley EFI equipped with drive-by-wire make sure the Global Folder is set up properly based on the

“Software Setup” above. The drive-by-wire is initialized when the ignition is turned on. So if you send a Global Folder with a drive-by-

as the pedal is depressed. Make sure the throttle plate returns to the “idle” position when the accelerator pedal is no longer

depressed.

5

6